1. Field of the Invention
This invention relates to a display device, and more specifically, to a display device equipped with light-emitting devices having a resonator structure.
2. Description of the Related Art
In recent years, lighting devices and organic electroluminescence display devices (hereinafter simply called “organic EL display devices”) making use of organic electroluminescence devices (hereinafter simply called “organic EL devices”) are finding widespread utility. Concerning organic EL display devices, there is a strong demand for the development of a technology that makes it possible to realize an efficient output of light, because a low light output efficiency means ineffective utilization of an actual luminous quantity in an organic EL device and becomes a cause of a significant loss in power consumption or the like.
Under these circumstances, several technologies have been proposed for organic EL display devices. A technology that is intended to achieve an improvement in light output efficiency by the arrangement of a protuberance structure is disclosed, for example, in JP-A-2003-077648 (hereinafter referred to as Patent Document 1). A technology that is intended to achieve an improvement in light output efficiency by the arrangement of microlenses is disclosed, for example, in JP-A-2002-184567 (hereinafter referred to as Patent Document 2) or JP-T-2005-531102 (hereinafter referred to as Patent Document 3). Further, organic EL display devices having various reflectors, including the structure of a compound parabolic concentrator (CPC) useful as a concentrator for a solar battery, are also disclosed in Patent Document 3.
It has also been attempted to control light, which is to be generated in a light-emitting layer, by introducing a resonator structure, for example, to improve the color purity of the light or to increase the efficiency of light emission (see, for example, WO 01/39554 A1, hereinafter referred to as Patent Document 4). It is also disclosed, for example, in Japanese Patent No. 3703028 (hereinafter referred to as Patent Document 5) that the intensity of light emission can be maximized by controlling light, which is generated in a resonator structure, and light beams, which are reflected back from its reflection end portions, into a mutually-intensifying relation.